listView显示对象以及access any RESTFull service that uses JSON

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    >
<ListView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/lstText"
    />
</LinearLayout>listitems.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent" android:layout_height="fill_parent">
 <LinearLayout
 android:orientation="vertical"
 android:layout_width="0dip" android:layout_weight="1"
 android:layout_height="fill_parent">
  <TextView
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:id="@+id/txtAlertText" />
  <TextView
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:id="@+id/txtAlertDate" />
 </LinearLayout>
</LinearLayout>package josecgomez.com.android.dev.webservice;
import java.util.List;
import josecgomez.com.android.dev.webservice.objects.alerts;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.TextView;public class AlertsAdapter extends ArrayAdapter<alerts> {
 int resource;
 String response;
 Context context;
 //Initialize adapter
 public AlertsAdapter(Context context, int resource, List<alerts> items) {
  super(context, resource, items);
  this.resource=resource; }
 @Override
 public View getView(int position, View convertView, ViewGroup parent)
 {
  LinearLayout alertView;
  //Get the current alert object
  alerts al = getItem(position);  //Inflate the view
  if(convertView==null)
  {
   alertView = new LinearLayout(getContext());
   String inflater = Context.LAYOUT_INFLATER_SERVICE;
   LayoutInflater vi;
   vi = (LayoutInflater)getContext().getSystemService(inflater);
   vi.inflate(resource, alertView, true);
  }
  else
  {
   alertView = (LinearLayout) convertView;
  }
  //Get the text boxes from the listitem.xml file
  TextView alertText =(TextView)alertView.findViewById(R.id.txtAlertText);
  TextView alertDate =(TextView)alertView.findViewById(R.id.txtAlertDate);  //Assign the appropriate data from our alert object above
  alertText.setText(al.alerttext);
  alertDate.setText(al.alertdate);  return alertView;
 }}

package josecgomez.com.android.dev.webservice;

import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import josecgomez.com.android.dev.webservice.objects.alerts;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListView;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

public class main extends Activity {
    /** Called when the activity is first created. */
	//ListView that will hold our items references back to main.xml
	ListView lstTest;
	//Array Adapter that will hold our ArrayList and display the items on the ListView
	AlertsAdapter arrayAdapter;

	//List that will  host our items and allow us to modify that array adapter
	ArrayList<alerts> alrts=null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //Initialize ListView
        lstTest= (ListView)findViewById(R.id.lstText);

         //Initialize our ArrayList
        alrts = new ArrayList<alerts>();
        //Initialize our array adapter notice how it references the listitems.xml layout
        arrayAdapter = new AlertsAdapter(main.this, R.layout.listitems,alrts);

        //Set the above adapter as the adapter of choice for our list
        lstTest.setAdapter(arrayAdapter);

        //Instantiate the Web Service Class with he URL of the web service not that you must pass
        WebService webService = new WebService("http://www.sumasoftware.com/alerts/GetAlerts.php");

        //Pass the parameters if needed , if not then pass dummy one as follows
		Map<String, String> params = new HashMap<String, String>();
		params.put("var", "");

		//Get JSON response from server the "" are where the method name would normally go if needed example
		// webService.webGet("getMoreAllerts", params);
		String response = webService.webGet("", params);

		try
		{
			//Parse Response into our object
			Type collectionType = new TypeToken<ArrayList<alerts>>(){}.getType();

			//JSON expects an list so can't use our ArrayList from the lstart
			List<alerts> lst= new Gson().fromJson(response, collectionType);

			//Now that we have that list lets add it to the ArrayList which will hold our items.
			for(alerts l : lst)
			{
				alrts.add(l);
			}

			//Since we've modified the arrayList we now need to notify the adapter that
			//its data has changed so that it updates the UI
			arrayAdapter.notifyDataSetChanged();
		}
		catch(Exception e)
		{
			Log.d("Error: ", e.getMessage());
		}
    }
}

 Please note that the attached jar file contains a compiled copy of the GSON library available at http://code.google.com/p/google-gson/.

以上是转帖 http://www.josecgomez.com/2010/05/04/android-accessing-restfull-json-services-library/

http://www.josecgomez.com/2010/04/30/android-accessing-restfull-web-services-using-json/